Methods: The IRFACODE II study is a retrospective, non-randomized open access study for centres with a minimum of about 50 patients to evaluate the safety and side effects of ASD closure with this device. A minimum of 2000 patients that have an ASD II closed with this device until 31. June 2016 will be enrolled, the follow-up will be until 31. June 2017. Primary outcome measures for safety are the amount of erosions over a minimum follow-up time of 12 months. Primary outcome measures for device performance will include the success of complete ASD closure. Secondary outcome measures for safety will include the technique of implantation, the success rate in anatomically difficult ASDs, the incidence of arrhythmias (AV block, atrial fibrillation or flutter), device embolization, embolic events or migraine. A subgroup analysis according to patients age and anatomy of the defect will be performed.